1. Field of the Invention
Embodiments of the present invention generally relate to abatement of hazardous materials in a process chamber, and more particularly to a method and apparatus for reducing the level of metal hydrides that remain in the process chamber after semiconductor processing.
2. Description of the Related Art
During semiconductor substrate processing, reaction by-products, vapor, fumes, and other materials are routinely generated and need to be abated in accordance with various government safety guidelines. Currently, in order to make a process chamber safe to be opened after substrate processing, atmospheric air is repeatedly introduced into the process chamber to react with and neutralize the often toxic fumes or materials and subsequently pumped out of the chamber.
Generally, after depositing silicon material, such as metal-doped polysilicon, on a substrate inside a chemical vapor deposition (CVD) chamber, toxic gases, such as metallic gases, metal hydrides fumes, and transition oxides are generated at levels much higher than Permissible Exposure Limits. In order to reduce the level of metal hydride fumes to safe levels after substrate processing, atmospheric air needs to be pumped in a number of times (e.g., at least 100 cycles, each cycle lasting for about 15-20 minutes). This is a lengthy process, typically requiring days of pumping and purging the CVD chamber to reduce the level of metal hydride before the CVD chamber can be opened and available for another cycle of substrate processing.
Therefore, there is a need for a technique to cost effectively abate post-processing toxic materials and safely shorten the amount of abatement time, such that the cycle time required for substrate processing is reduced.